1. Field of the Invention
This invention relates to couplings and, in particular, this invention relates to couplings for joining fluid conductors such as hoses.
2. Background
Male and female couplings are used to connect fluid conductors, such as hoses or lines conveying liquids or gases when the desired connection is nonpermanent. The female couplings may have a latch plate slidably disposed in a female coupling body. The latch plate contains an opening large enough to accommodate a portion of the male coupling. Accordingly, when the male coupling is mated to the female coupling, a portion of the male coupling is inserted into the female coupling, then locked in place by engaging an edge of the latch plate in a slot defined in the male coupling. To separate mated male and female couplings, the latch plate edge is disengaged from the male coupling slot and the male coupling is removed from within the female coupling. In many female coupling bodies, the latch plate is operably secured in place first by biasing the latch plate toward a locked position and second by extending a latch pin through an opening present in a lower portion of the latch plate.
The necessity of a separate opening to accommodate the latch pin, in turn, requires latch plates to be manufactured in a minimum size, which is incompatible with many existing female couplings. Additionally, it was believed that latch plates having intersecting openings, as described above, possessed insufficient strength for use and would detach if twisted.
In one type of failure, coupled male and female couplings can disconnect when a rotary and pulling force is exerted thereon. The cause for this type of failure is believed to be that the latch plate can catch a larger diameter on the slot of the mating male plug, thereby causing the male plug to “unthread” or causing the latch plate to displace from the larger diameter groove in the male plug due to the effect of the twisting and pulling forces.
Another type of failure in couplers of the prior art is believed to be caused by intersecting latch plate openings for the male plug and latch pin. Due to these intersecting openings, mated male and female couplers were believed to be more likely to disconnect if twisting and pulling forces were exerted on mated male and female couplings. Accordingly, a latch plate with separate openings for the latch pin and male plug was developed. While largely solving the problem of failed matings due to torsional forces, the latch plate was necessarily larger than latch plates with intersecting openings because of the minimum sizes of the two openings and minimum amount of latch plate material required between the openings. As a consequence of the larger latch plate, larger coupling bodies became necessary to accommodate the larger latch plates therewithin. The larger coupling bodies and latch plates required higher amounts of material, therefore were more expensive to manufacture. Moreover, the larger latch plates could not be used to retrofit many of the existing coupling designs, which were too small for the larger latch plates.
There is then a need for a female coupling which is resistant to being detached from a mated male plug and which is sufficiently small to allow retrofitting the latch plate to existing designs and dimensions.
By way of illustration and not limitation, the male couplings of the prior art may swivel freely when seated in the female couplings of this invention. While often a desirable feature, rotating freely when seated in a female coupling may induce undesirable consequences as well. One of these undesirable consequences is the increased likelihood of inadvertent disconnection due to torsional forces present during rotation. Additionally, free rotation may result in an undesirable non-uniform orientation of features such as latch plates on a row or array of seated male couplings. Non-uniform latch plates may also make it more difficult to remove or disconnect the male couplings. Accordingly and in some embodiments, it may be desirable to seat a male coupling into the female coupling of this invention, which will not swivel or rotate when seated.